Intermittent Fasting vs. Carb Restriction

 My master's dissertation was on the subject of fasting. Many benefits of the practice were known when I wrote on the topic in 1972 but science has come a long way since. We now know how fasting provides benefits at the molecular level through autophagy--literally "self eating". Fasting is difficult for many people even though they would like the benefits the practice offers.

A recent study suggests that restriction of carbohydrates without restriction of calories may provide many of the benefits of fasting. The researchers conclude: " These findings demonstrate that carbohydrate restriction, without altering energy intake, can elicit effects similar to those observed in short-term fasting. As such we propose a strategy of repeated carbohydrate restriction cycles alone may be an emerging alternative approach for the enhancement of cardiometabolic health, warranting further investigation."

Reference:

Article on the benefits of fasting.

Article on carbohydrate restriction providing benefits of fasting.

 Regulating a Sweet Tooth

     Professor Matthew Potthoff and his associates have identified the first hormone ever shown to specifically regulate sugar intake. The liver produced hormone is called fibroblast growth factor 21 (FGF21 for short). The hormone suppresses the consumption of simple sugars. The production of the hormone is triggered by consumption of large quantities of carbohydrate. The hormone also improves insulin sensitivity.

     Normal mice injected with FGF21 consumed seven times less sugar when given the opportunity than did normal mice. This study suggests that strict avoidance of carbohydrates may result in sugar cravings undermining efforts of those who are obese to lose weight or of diabetics to control blood sugars.

Reference:

Cell Metabolism, von Holstein-Rathlou and BonDurant et al: "FGF21 Mediates Endocrine Control of Simple Sugar Intake and Sweet Taste Preference by the Liver" dx.doi.org/10.1016/j.cmet.2015.12.003 

The Danger of Overcooked Foods

     When high carbohydrate foods are browned or blackened a substance called acrylamide is formed. Very high levels of this substances are found in potato chips, french fries, many commercial breakfast cereals, bread crust, toast, and roasted coffee beans. The federal government limits the amount of acrylamide in drinking water to 0.5 parts per billion. Unfortunately, a six-ounce serving of French fries provides about 500 times the allowable limit of acrylamide. Acrylamide is a suspected carcinogen.
     It is always best to try and avoid overheated foods. For example, oatmeal, cream of wheat, or muesli would be free of acrylamide since they are not overly heated.